Rubber-sprung rail wheels of this kind are known in diverse embodiments, for example, from DE-PS 594 792, DE 32 01 499 A1 or DE 24 06 206 A1.
The disadvantage of the usual rubber-sprung rail wheels used in the manufacture of rail vehicles is that these deflect only a maximum of 1 mm in radial direction. However, a deflection of up to 5 mm is desired under the same load.
Highly elastic rail wheels purely with thrust load or with superposed thrust and pressure loads are likewise known. For example, a rail wheel is known from U.S. Pat. No. 6,312,033 wherein the rubber ring is loaded vertically and in thrust so that the rubber ring takes up a high radial deflection.
However, it is disadvantageous with respect to known highly elastic rail wheels that their durability is not satisfactory. In addition to the vertical load because of the weight of the vehicle, a lateral transverse force acts additionally on the rubber body. In the static state, this force effects a cardanic tilting of the rail wheel and the center of rotation is disposed one-third above the center point of the wheel. In the traveling state, the tilting changes continuously over the periphery. In this way, a high peripheral edge pressing arises at the outer diameter of the wheel which destroys the rubber body or rubber ring in a relatively short time.
In order to reduce the edge pressing, it has been shown to be advantageous to increase the wall thickness of the rubber rings. However, for small wheels such as are used in street cars, this is not adequately possible. It is furthermore disadvantageous that the rings deflect too greatly because of the larger wall thicknesses with the technically usable rubber hardness. The intense deflection can be compensated by superposing thrust loads and pressure loads in the rubber body, for example, by placing the rubber rings at an angle. However, the edge pressing is again increased and the service life of the rubber body is further deteriorated. The reasons against a continuous conical configuration of the rubber ring is that the structural space for an overall satisfactory wall thickness is mostly not sufficient.
For the deflection, it is therefore advantageous to have a narrow wall thickness of the rubber rings but for the edge pressing, the wall thickness should be as large as possible.